Nanoparticles contain hundreds to thousands of single molecules or atoms and have long been recognized as having enhanced chemical and physical properties compared with their bulk forms. Nanoparticles having alloys manufactured from precious metals are of special importance for their catalytic and magnetic properties, useful in information storage media, magnetic refrigeration, audio reproduction and magnetic sealing. Transition metals such as palladium, platinum and cobalt are well known for their catalytic capabilities in bulk and deposited phases. Such alloys can be fabricated through bulk metal processes or through nanoparticle synthesis. It has recently been realized that these nanoparticles with uniformity in size, shape and internal structure could be used as unique building blocks to fabricate nanoparticles-based functional structures by self-assembly. Generally, this nanoparticle-based self-assembly is governed by the nature of the interactions exhibited among the stabilized particles. Various monodisperse nanoparticle materials, including polymers, semiconductors, and metals, have been tested for use in building self-assembly nanoscale devices.
While such nanostructures can be used for manufacturing nanoscale devices, these manufacturing processes are generally expensive and time consuming. In addition, the number of such structures that can be obtained is limited. It is therefore desirable to develop inexpensive and simple methods by which nanoparticle films can be easily generated upon surfaces of solids, and further, it is desirable to use such films for a variety of commercial applications, most notably for the development of analytical techniques that have high sensitivities.